The present invention relates to an apparatus and method of detecting the occurrence of overloads in circuit and more particularly for detecting the time, duration and strength of an overload or power surge.
The need to provide protection for electrical and electronic circuits and systems has existed from the advent of these systems in the late 1800""s. To date a variety of devices have been developed to protect a circuit, electric or electronic system from damage or destruction by power or voltage surges.
One popular type of surge protection device in current use is the gas discharge tube. Gas discharge tubes are typically two lead devices with an anode and cathode lead. Typically one of the leads is connected to a power input lead of the system to be protected and the other connected to ground. When a surge occurs at the power input of the system to be protected the gas discharge tube diverts the surge to ground. The tube does this by ionization of gas within the tube. In effect the tube short circuits the surge to ground.
One of the short comings of these surge protection systems, in particular those that use a gas discharge tube is that no record is retained of the occurrence of a power surge. Retaining a record may be important in situations where the system to be protected is located in a remote location such a security gate system. Frequent power surges may indicate a variety of problems with the remote system that need to be addressed to prevent injury or eventual destruction of the system being protected.
Thus, what is needed is an efficient and economical system to record and analyze the occurrence of power surges. There is a further need to provide a system for recording and analyzing power surges that is cost effective to fabricate and implement.
It is an objective of the present invention to provide and efficient and economical system to record and analyze the occurrence of power surges in a system. It is a further objective to provide a system for recording and analyzing power surges that is cost effective to manufacture and easy to implement.
The present invention accomplishes these and other objectives by providing an apparatus for detecting and recording episodic overloads in a circuit, the apparatus having: a) a gas discharge tube with at least a first and second terminal with the first terminal connected to an input line of a circuit and the second terminal connected to ground, the tube being configured to be activated when a voltage in the security circuit reaches a threshold level and at the threshold level and above the tube becomes active and diverts power from the circuit to ground causing a discharge in the gas discharge tube; b) a light sensitive sensor adjacent to the discharge tube and encased with the gas discharge tube in light impervious housing to thereby exclude ambient tight and make the light sensor subject to exposure only to light produced by the gas discharge tube; c) a diagnostic device connected to the light sensitive sensor wherein when the tight sensitive sensor reacts to light generated by activation of the gas discharge tube the sensor reacts in concert and produces a signal representative of the discharge of the gas discharge tube which the diagnostic device records information derived from the signal generated by the sensor; and d) wherein the information derived from the signal generated by the sensor and recorded by the diagnostic unit with respect to a discharge in the gas discharge tube includes a time of the discharge, an amplitude of the discharge and a duration of the discharge.